Which VPN are you using? Which server? If possible, attach a screenshot of your VPN window.
are u sure ur vpn is japan? or u are using ones simmilar to hotspot cuz clearly ur vpn either is not set on japan or its not even working try using a simple one like vpn gate
use another japan vpn then 1 should definitly work
does your browser run on proxy? you might want to disable it if you have one or you could reset the settings of your browser and try it again.